Only one machine 10.10.10.20 on my LAN is firewalled with the rules below.
That machine intermittently experienced slow browsing, until last night it simply started timing out all web pages.
I dropped firewall and browsing was fast again like on all other machines. Rules follow (all of them):

The router is a P4-2.2 GHz machine with 512 MB RAM booted from a 2.0RC3 CD with profiles saved onto a Kingston 16GB DataTraveler USB key.
I really need the rules above to work. How can I ensure that both rules are turned on and browsing is OK?